Philips Semiconductors
Product specification
Low voltage high performance mixer FM IF
system with high-speed RSSI
SA626
DESCRIPTION
The SA626 is a low-voltage high performance monolithic FM IF
system incorporating a mixer/oscillator, two limiting intermediate
frequency amplifiers, quadrature detector, high speed logarithmic
received signal strength indicator (RSSI), voltage regulator and
audio and fast RSSI op amps. The SA626 is available in 20-lead
SOL (surface-mounted small outline large package) and 20-lead
SSOP (shrink small outline package).
The SA626 was designed for high bandwidth portable
communication applications and will function down to 2.7V. The RF
section is similar to the famous NE605. The audio and RSSI
outputs have amplifiers. The RSSI output has access to the
feedback pin. This enables the designer to level adjust the outputs
or add filtering.
SA626 incorporates a power down mode which powers down the
device when Pin 8 is low. Power down logic levels are CMOS and
TTL compatible with high input impedance.
PIN CONFIGURATION
D and DK Packages
RF
IN
1
20 MIXER OUT
19 IF AMP DECOUPLING
18 IF AMP IN
17
IF AMP DECOUPLING
RF BYPASS 2
XTAL OSC EMITTER
XTAL OSC (BASE)
V
CC
3
4
5
16 IF AMP OUT
15 GND
14 LIMITER IN
13
12
11
LIMITER DECOUPLING
LIMITER DECOUPLING
LIMITER OUT
RSSI FEEDBACK 6
RSSI
OUT
7
POWER DOWN CONTROL 8
AUDIO OUT 9
QUADRATURE IN 10
SR00470
APPLICATIONS
•
Digital cordless telephones
•
Digital cellular telephones
•
Digital cellular base stations
•
Portable high performance communications receivers
•
Single conversion VHF/UHF receivers
•
SCA receivers
•
RF level meter
•
Spectrum analyzer
•
Instrumentation
•
FSK and ASK data receivers
•
Log amps
•
Wideband low current amplification
FEATURES
•
Mixer input to >500MHz
•
Mixer conversion power gain of 11dB at 240MHz
•
Mixer noise figure of 14dB at 240MHz
•
XTAL oscillator effective to 150MHz (L.C. oscillator to 1GHz, local
oscillator can be injected)
Figure 1. Pin Configuration
•
92dB of IF Amp/Limiter power gain
•
25MHz limiter small signal bandwidth
•
Temperature compensated logarithmic Received Signal Strength
Indicator (RSSI) with a dynamic range in excess of 90dB
•
Audio output internal buffer
•
RSSI output internal buffer
•
Internal op amps with rail-to-rail outputs
•
10.7MHz filter matching (330Ω) reduces external component
count; suitable for crystal/ceramic/LC filters
•
Fast RSSI rise and fall times
•
Low power consumption: 6.5mA typ at 3V
•
Power down mode (I
CC
= 200µA)
•
Excellent sensitivity:
0.54µV into 50Ω matching network for 12dB
SINAD (Signal to Noise and Distortion ratio) for 1kHz tone with RF
at 240MHz and IF at 10.7MHz
•
SA626 meets cellular radio specifications
•
ESD hardened
ORDERING INFORMATION
DESCRIPTION
20-Pin Plastic Small Outline Large (SOL) package (Surface-mount)
20-Pin Plastic Shrink Small Outline Package (Surface-mount)
TEMPERATURE RANGE
-40 to +85°C
-40 to +85°C
ORDER CODE
SA626D
SA626DK
DWG #
SOT163-1
SOT266-1
1997 Sept 25
2
853-1723 18427
Philips Semiconductors
Product specification
Low voltage high performance mixer FM IF system
with high-speed RSSI
SA626
AC ELECTRICAL CHARACTERISTICS
T
A
= 25
°
C; V
CC
= +3V, unless otherwise stated. RF frequency = 240.05MHz + 14.5dBV RF input step-up; IF frequency = 10.7MHz; RF level =
-68dBm; FM modulation = 1kHz with
±125kHz
peak deviation. Audio output with C-message weighted filter and de-emphasis filter. Test circuit
Figure 1. The parameters listed below are tested using automatic test equipment to assure consistent electrical characteristics. The limits do
not represent the ultimate performance limits of the device. Use of an optimized RF layout will improve many of the listed parameters.
LIMITS
SYMBOL
PARAMETER
TEST CONDITIONS
MIN
Mixer/Osc section (ext LO = 160mV
RMS
)
f
IN
f
OSC
Input signal frequency
External oscillator (buffer)
Noise figure at 240MHz
Third-order input intercept point
Conversion power gain
RF input resistance
RF input capacitance
Mixer output resistance
IF section
IF amp power gain
Limiter amp power gain
Input limiting -3dB
AM rejection
Audio level
Audio DC level
SINAD sensitivity
THD
S/N
Total harmonic distortion
Signal-to-noise ratio
IF RSSI output with buffer
No modulation for noise
IF level = -118dBm
IF level = -68dBm
IF level = -10dBm
IF RSSI output rise time
(10kHz pulse, no 10.7MHz filter)
(no RSSI bypass capacitor)
IF RSSI output fall time
(10kHz pulse, no 10.7MHz filter)
(no RSSI bypass capacitor)
RSSI range
RSSI accuracy
IF input impedance
IF output impedance
Limiter input impedance
Limiter output impedance
Limiter output level with no load
RF/IF section (int LO)
Audio level
System RSSI output
System SINAD
RF level = -10dBm
RF level = -10dBm
RF level = -106dBm
160
1.4
12
mV
RMS
V
dB
IF frequency = 10.7MHz
RF level = -56dBm
RF level = -28dBm
IF frequency = 10.7MHz
RF level = -56dBm
RF level = -28dBm
2.0
7.3
90
+1.5
330
330
330
300
130
µs
µs
dB
dB
Ω
Ω
Ω
Ω
mV
RMS
1.2
1.1
µs
µs
0.3
0.9
Test at Pin 18
80% AM 1kHz
Unity gain
Pin 9, no signal
IF level = -111dBm
120
38
54
–105
50
160
1.0
16
-43
60
0.2
0.6
1.3
0.5
1.0
1.8
–38
200
dB
dB
dBm
dB
mV
RMS
V
dB
dB
dB
V
V
V
(Pin 20)
Matched f1=240.05; f2=240.35MHz
Matched 14.5dBV step-up
Single-ended input
8
500
500
14
-16
11
700
3.5
330
14
MHz
MHz
dB
dBm
dB
Ω
pF
Ω
SA626
TYP
MAX
UNITS
1997 Sept 25
4
Philips Semiconductors
Product specification
Low voltage high performance mixer FM IF system
with high-speed RSSI
SA626
9.0
8.5
8.0
7.5
7.0
6.5
V
CC
= 2.7V
6.0
5.5
5.0
–50 –40 –30 –20 –10 0 10 20 30 40
TEMPERATURE (°C)
V
CC
= 3V
V
CC
= 5V
0.50
0.45
POWER DOWN SUPPLY CURRENT (mA)
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0.00
–50 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 90 100
TEMPERATURE (°C)
V
CC
= 2.7V
V
CC
= 3V
SUPPLY CURRENT (mA)
V
CC
= 5V
50
60
70 80 90
Supply Current vs Temp and Supply Voltage
20
19
18
17
MIXER GAIN (dB)
16
15
14
13
12
11
10
9
8
7
6
5
–50 –40 –30 –20 –10
0
10 20 30 40
50
60
70 80 90
V
CC
= 2.7V
V
CC
= 3V
V
CC
= 5V
Power Down Supply Current vs Temp and Supply Voltage
–6
THIRD ORDER INPUT INTERCEPT POINT dBm)
–8
–10
–12
–14
–16
–18
–20
–22
–24
–26
–28
–30
–50 –40 –30 –20 –10
0
10 20 30 40
50
60
70 80 90
V
CC
= 3V
V
CC
= 5V
V
CC
= 2.7V
TEMPERATURE (°C)
TEMPERATURE (°C)
Mixer Power Gain vs Temperature and Supply Voltage
300
275
Third Order Input Intercept Point vs Temp and Supply Voltage
20
AUDIO
0
250
225
200
AUDIO (mV)
175
150
125
100
75
50
25
0
–50 –40 –30 –20 –10
–120
0 10 20 30 40
TEMPERATURE (°C)
50
60
70 80 90
–50 –40 –30 –20 –10 0 10 20 30 40 50
TEMPERATURE (°C)
60
70 80 90
–100
12dB SINAD
V
CC
= 3V
V
CC
= 2.7V
–80
NOISE
V
CC
= 5V
AUDIO (dB)
–40
DISTORTION
–60
–20
AM REJECTION
Audio Output Level vs. Temp and Supply Voltage
12dB SINAD and Relative Audio, THD, Noise and AM
Rejection for VCC = 3V vs Temperature RF = 240MHz,
SR00472
Level = –68dBm, Deviation = 125kHz
Figure 3. Performance Characteristics
1997 Sept 25
5
Analog electronics
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